Slip lifter lock



suitable actuating pressure fluid such as air, gas,.

steam, liquid or the like. As shown, cylinder 23,

is mounted on arm I8 and, therefore, also sup ported by pedestal I9.

Cylinder 23 is tted at its opposite. en ds uwith ttings 24 and 25 for the introduction vand' disi" charge of the iiuid employed in the cylindentojfactuate piston rod 22. Pipes 26 and 21 connect fittings 24 and 25, respectively, to a three-way contro1 valve 28, which is of conventional design, the form illustrated in Fig. 1 being manufactured commercially by Hydraulic Products Company, Chicago, Illinois. A pipe 29 connectsvalve v2S to an appropriate source of a suitable actuating pressure fluid. A back-pressure valve, designated generally by the numeral 30, is interposed in pipe 21 andis provided at one end with aside fitting 3| which is connected by means of a pipe 32 to the inlet 33 of a dash pot 34 which is fitted with a plunger 35. Dash pot 34 i's` rigidly fastened at 36 to upper plate I6 of the hinge support bracket and extends downwardly therefrom.

A bracket 31 mounted on the end 'of low'e'rfplate I1 of the hinge support bracket provides 'pivotal support by means of a pin 38 for a latch member, designated generally by the numeral 39, andcon'- sisting of a generally vertical arm 4D having a horizontal arm 4| rigidly .connected thereto. Vertical arm 48 has an offset portion 42 at its upper end forming a shoulder 43 adapted to engage hinge pin 'I I. Horizontal arm 4I extends below the end of plunger 35 which is in constant engagement therewith and has mountedon its upper face an eye 44 located between.' the'point of contact of plunger 35 with horiz'ontal',"""n'i 4I and the junction of' horizontal arm 4I 'with' l cal arm 4,0. Upper plate I6'offthe-hinge'suiort bracket has mounted onithe lowerfac aneye 45 is connected between eyes Land ',45jan'dfi'snormally in tension. 1'.' l Back pressure Valve 3ilinclude's'aholloir'/v ylindrical body 41 tted with a'f'cap portion .48' which 55 is screwed into body 41, forming generallyan extension thereof. Cap portion.48 ,is'ttedw'ith a threaded connection 49ffor,'attachment'ofpipe 21. The bore of cap portion. 4.8v .is v'slightl'ylsmaller in diameter than the '.bore of .bodyII'I forming an annular shoulder 50 which is adaptedltotfs'erve as a valve seat and is appropriately"taperedfr this purpose.

Body 41 has mounted in `the bore thereof 1.a valve member 5| of smaller diameter; thalthe bore of body 41. Valve memberl 51|' is'alsoboidj internauy at 52 andV is provided with'a'tap'red head 53 of somewhat larger diameter fthnv'alve member 5| and adapted to seat against" shoulder 50. The upper end of bore' 52 is `charnfered to form an outwardly tapering seat 52g". Valve -member 5| is provided at the end opposite to tapered head 53 with a flange 54, the outer' circumference of which formsa 'sliding fit wilil'the interior wall ofthe'bore of body.41.

4 extend through flange 54 and provide communication between the bore of body 41 belowvalve member 5I and the annular space 56 between valve member 5| and the bore of body 41 above flange 54. Passageways 51 extend through tapered head 53 to provide communication between annular space 56 and bore 52 adjacent seat 52a. The lower end of body 41 is fitted with an internally threaded connection 58 for connection into pipe 21`. v Side outlet 3l communicates with `the bore ofi connection 58. The bore of body 41 is reduced at the point of attachment to connec- =.tion 58 forming a tapered shoulder 59. A coil spring 60 is mounted in the bore of body 41 be- -twe'en' the lower face of flange 54 and shoulder 59 andisnormally in compression to normally force ,headj53 of valve member 5| into engagement `v"'witlfrshoulder 5l): A tappet type valve is mounted in bore ,52 and consists of a head 6| adapted to be seated in seat 52a and a stem 62 which extends through bore 52 and for a short distance beyond Qthe lower face of flange 54. A coil spring 63 of smaller' diameter than coil spring 60 surrounds the extending endof stem 62 and is held in compression against the lower face of flange 54 by means of nuts 64 screwed on the end of stem 62.

The inner end of plunger 35 is fitted with a resilient cup`65 which is fastened in place by means ofa clafp'fs'crew 66 which is inserted through a iihg61 mounted 'on the cup and screwed into the end of"the"plu'n'ger. The cap screw compresses the cup and forces it into sealing engagement with the inner wall ofthe dash pot. A passageway 68 provides communication between lnlet 33 and the interior of dash pot 34 above cup 65. The operation of the structure above described will nowbe explained, referring rst to parts as illustrated in .full lines in Fig. 1. As there shown, slips Gand 'thesupporting spider 5 are in the raised or retracted position, resulting from the admission of actuating iluid through pipe 29, control valvev28, pipe 26 and connection 24 into the forward end of cylinder 23 which forces pistonf2-2 rearwardly' in cylinder 23. This movement acts on lever arm 20, thence through hinge arms 9 and I0 and hinge pins II-I2 and j|3-.-I4 to raise spider 5 and its attached slips 6 to the position shown.A The operation of control valve 28 in effecting these movements is tn place the exhaust'of th'e control valve in communication with pipe 21, thence to connection at the rear end of cylinder 23. These connections thus become an exhaust system for the actuating iiuid in the rear end of cylinder 23. The actuating pressure fluid'exhausts through pipe 21 into the interior of back-pressure valve vwhere the exhausting fluid' forces valve'imember 5| downwardly and ,away from shoulder. 50 andv permits the fluid to jilo'w pastI vvalvehead 53 through annular space '5 6 and ports55, thence through connection 58 vtothe exhaust passage of control valve 28. This system being in exhaust, pressure is also relieved from the top of plunger through inlet 33 and pipe 32 and ,connections 3| and plunger 35 is thus forced into'retracted position by the coun- Iter-action of lcoil spring 46 acting to pull arm l4I of thesafety latch upwardly against the end ofthe plunger'.l This action of arm 4I operates throughhinge pin 38 to swing the vertical arm ofvv the latch forwardly and bring offset shoulder" 43, into. latching engagement underneath 'hinge pin Il, thereby locking spider 5 in the 'raised position as shown.

` Irr order to lower slips 6 into -slip bowl 4, the

'of contro1 valve 2B is turned in a conventional and appropriate manner to place the exhaust passage of this valve in communication with pipe 26 and, at the same time, to place the source of actuating pressure fluid through pipe 29 into communication with pipe 21. The actuating fluid passing through rpipe 21 enter--` ing the lower end of back pressure valve 30 through inlet 58 forces valve member 5I up-A wardly and head 53 against shoulder 50. This forces the pressure fluid to .be diverted through passageways 51 against head 6| of the tappet valve, lifting it from seat 52a and admitting the fluid into the upper part of valve 30, thence through connection 49 and pipe 21 to the rear end of cylinder 23. There the fluid acts to drive piston 22 forward which, acting through the linkage previously described, will operate to lower the spider 5 and slips 6. However, this action could not occur until the latch is disengaged from hinge pin Il. The disengagement is effected automatically while the actuating fluid is flowing to the rear end of cylinder 23, as previously described. While the fluid is flowing through back pressure valve 30 to the rear end of cylinder 23, the system is under pressure of the fluid, and the fluid, therefore, also flows through connection 3|, pipe 32 and inlet 33 into dash pot 34 where it acts on the top of plunger 35 to force it downwardly against the free end of latch arm 4|. This forces the latter downwardly and acts to drive arm 40 yof the latch rearwardly and out of engagement with hinge pin ll, thereby releasing spider 5 and allowing it to be lowered by the action of piston 22 and the inter-connecting linkage previously described. The position of the parts of the latch operating mechanism when the latch is thus disengaged is shown in dashed outlines in Fig. l.

While piston 22 is being forced forward by the action of the fluid entering the rear of cylinder 23, the fluid in the forward end of the cylinder will be exhausting through connection 24 once, the slips are in the raised position, they are automatically held locked in that position and are not subject to the usual hazards attendant upon drilling and servicing operations.

While air is the preferred actuating fluid for use with the embodiment of the invention herein described, it will be understood that other pneumatic or hydraulic pressure fluids may ybe used with advantage.

Where desired, dash pot 34 may be connected directly to a source of pressure fluid, and the locking mechanism may be operated thereby independently of the system employed to operate Y the raising and lowering mechanism.

It will be understood that various alterations and modifications may be made in the details of the structure herein described without departing from the scope of the appended claims but within the spirit of this invention.

What I claim and desire to secure by Letters Patent is:

1. Apparatus for operating a slip spider, cornprising, a lifting yoke attachable to a slip spider, a reciprocating piston connected to said yoke and actuable by fluid pressure to raise and lower same, a pivoted latch element normally disposed in the path of downward movement of said yoke, a plunger engaged with said latch element and actuable by fluid pressure to move said latch element out of said path, and means for supplying actuating fluid sequentially first to said plunger and second to said piston when the latter is to be moved in a direction to lower said yoke, said means comprising a pressure fluid supply conduit connecting said piston with said plunger, and back-pressure check valve means interposed in said conduit automatically operative by the fluid flowing therethrough toward said piston to divert a portion thereof to said plunger in advance of that flowing toward said piston.

2. Apparatus for operating a slip spider, coniprising, a lifting yoke attachable to a slip spider, a reciprocating piston connected to said yoke and actuable by fluid pressure to raise and lower same, a pivoted latch element disposed below said yoke for movement into and out of the path of movement thereof, an operating arm connected to said latch element, spring means connected to said arm to normally yieldably urge said latch element into said path, a plunger engaged with said arm and actuable by fluid pressure to move said latch element out of said path, means for supplying actuating fluid sequentially first to said plunger and second to said piston when the latter is to be moved in a direction to lower said yoke, said means comprising a pressure fluid supply conduit connecting said piston with said plunger, and .back-pressure check valve means interposed in said conduit automatically operative .by the fluid flowing therethrough toward said piston to divert a portion thereof to said plunger in advance of that flowing toward said piston.

BENJAMIN F. KELLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 459,212 Brockway Sept. 8, 1891 512,313 McDonald Jan. 9, 1894 1,341,702 Black June 1, 1920 1,574,404 Moody Feb. 23, 1926 2,063,378 Hiniker Dec. 8, 1936 2,076,042 Penick et al Apr. 6, 1937 2,139,185 Engel Dec. 6, 1938 2,201,189 Makarof et al May 21, 1940 2,231,923 Koen Feb. 18, 1941 2,340,597 Kelley Feb. 1, 1944 2,351,887 Steadman June 20, 1944 

